Flyback converter NCP1651

[rahat5810]

Hi
I need a flyback converter with PFC. I used NCP 1651 from on semi. I used the application notes and the design aid spreadsheet for my design. But it does not work. I even built the same circuit in the application note. But it also does not work.

Have any one workes with this ic? Or can any one recommend another ic to replace this one?

 

[Hero999]

Why don't you post your design and we might be able to suggest where you have gone wrong?

A link to the datasheets and other material you used to design it would be very helpful too.

 

[rahat5810]

Data sheet
https://www.electro-tech-online.com/custompdfs/2007/06/NCP1651-DPDF.pdf

Design aid spreadsheet
https://www.onsemi.com/pub/Collateral/NCP1651_DESIGN-D.XLS

Application note
https://www.electro-tech-online.com/custompdfs/2007/06/AND8124-DPDF.pdf

I built the exact same circuit in the application note, with the exception of MOSFET and Transformer.

 

[Hero999]

So, what was different about the MOSFET and the transformer?

Did you use a 2N7000 and a 50Hz mains transformer or something?

Without knowing exactly what you've done it's impossible to say.

 

[Nigel Goodwin]

Most likely problem is the transformer?, they are crucial items for switch-mode.

 

[rahat5810]

I used a high frequency ferrite core transformer. It has a turns ratio of 2:1 and a Lp of 8200uH. And the MOSFET I used was 2sk3116.

I have checked the transformer and MOSFET, they are both fine. I used a 100kHz square wave as gate pulse and got voltage at the secondary. So the MOSFET and the transformer are ok.

The problem seems to be in the NCP1651. It works in the test circuits given in
https://www.electro-tech-online.com/custompdfs/2007/06/TND308-DPDF.pdf

but when I connect it in the main circuit it stoped working. After this it stopped working in the test circuits also.

 

[Hero999]

How is this assembled?

Is it on a real PCB or just bread board or vero board?

Do you think it might be a layout problem?

Have you contacted the manufacturer about the problem?

You might also be able to buy an evaluation kit to make experimenting easier.